The present invention generally relates to wireless communication systems, and particularly relates to controlling interference suppression in wireless communication receivers.
Interference suppression represents one of the more important mechanisms employed in wireless communication receivers to improve signal detection reliability. For example, Code Division Multiple Access (CDMA) wireless communication receivers often are configured with some form of interference suppression. Indeed, some of the more complex modulation formats being deployed in higher data rate wireless communication systems cannot be demodulated with acceptable error rates absent interference suppression at the receivers, at least under certain unfavorable channel conditions.
With interference suppression, a receiver attempts to characterize received signal noise and interference, such as by estimating one or more statistical properties. The receiver then uses those characterizations, which are dynamically updated to reflect changing reception conditions, to suppress at least a portion of that interference and noise. As an example, a receiver may be configured to suppress colored noise and interference by maintaining a dynamically updated matching filter that whitens the received signal, and thereby improves demodulation performance.
However, such processing may be marginally beneficial under at least some conditions. For example, when the received signal's interference plus noise spectrum is flat, e.g., white, interference suppression processing may not improve the receiver's performance. Further, the application of interference suppression during conditions when it is not needed represents needless expense in terms of operating power and computational overhead.